21008210507 has 2 divisors, whose sum is σ = 21008210508. Its totient is φ = 21008210506.

The previous prime is 21008210467. The next prime is 21008210551. The reversal of 21008210507 is 70501280012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21008210507 - 2¹² = 21008206411 is a prime.

It is not a weakly prime, because it can be changed into another prime (21008210807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10504105253 + 10504105254.

It is an arithmetic number, because the mean of its divisors is an integer number (10504105254).

Almost surely, 2^21008210507 is an apocalyptic number.

21008210507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21008210507 is an equidigital number, since it uses as much as digits as its factorization.

21008210507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 26.

Adding to 21008210507 its reverse (70501280012), we get a palindrome (91509490519).

The spelling of 21008210507 in words is "twenty-one billion, eight million, two hundred ten thousand, five hundred seven".